In order to operate properly, an integrated circuit (IC) connected to a power supply needs to be supplied with a DC voltage whose level remains constant within a certain tolerance range. Integrated circuits comprising modern application processors are provided in packages which may introduce parasitic resistances R, inductances L and capacitances C which may result in a distinct dependency of the voltage supplied to the integrated circuit device on the characteristic over time of the current consumed by the integrated circuit device. High current consumption may, for example, be accompanied by a drop in the supply voltage, whereas fast, sharp changes of the consumed current may be accompanied by high frequency portions or voltage ripples added to the DC voltage signal received from the power supply.
Referring to FIG. 1, a sketch of a prior art supply voltage reaction on a sharp IC current change is schematically shown. The sketch illustrates a characteristic over time t of a supply voltage level U 10 provided to an integrated circuit in response to a sharp change of the IC current 12 drawn from the power supply. As shown, the supply voltage level 10 exhibits voltage ripples caused by the current level change at time T. These ripples may, for example, be reduced by employing an on-die decoupling capacitor.
In U.S. Pat. No. 6,717,389, a method for transient voltage reduction in a current controlled voltage regulator is described. It is shown that an always opened and controlled current source can be added in parallel to the actual current load to keep a total regulator current constant.
In U.S. Pat. No. 7,633,773, an on-die anti-resonance structure for an integrated circuit is described. The structure may reduce the effects of chip-package resonance in an integrated circuit assembly. This includes employing a series RLC circuit to reduce the output impedance of the power delivery system at the resonance frequency.